WASHINGTON - The nation's high school graduation rose again in the 2014-2015 school year, reaching a new record high as more than 83 percent of students earned a diploma on time, according to federal data released Monday.

The figures show gains among every group of students -- including white, black, Asian, Hispanic and Native American, as well as low-income students, students with disabilities and those learning English as a second language. The broad improvement continues a trend that began with the 2010-2011 school year, when states first adopted a uniform method of reporting graduation rates.

Gaps between student groups continued to close but remained large: Nearly 88 percent of white students graduated on time, 10 percentage points higher than Hispanic students (78 percent), 13 percentage points higher than black students (75 percent), and 16 percentage points above Native American and Native Alaskan students (72 percent).

Students with disabilities and English language learners have made larger-than-average gains since 2011, but the groups of students continue to graduate at rates far below average.

The White House released the data ahead of an event planned for Monday morning at Benjamin Banneker Academic High School in the District, where President Obama is expected to speak about his administration's record on education during the past eight years.

Iowa posted the highest rate in the nation, with 90.8 percent of students graduating on time, and New Mexico posted the lowest rate among the 50 states, with 68.6 percent of students graduating on time. Locally, both Maryland (87 percent) and Virginia (86 percent) reported graduation rates above the national average.

Experts say that high school graduation rates are an important measure of school success and academic progress, but they also say not to put too much stock in them: Requirements for graduation vary widely across states and can change over time.

In addition, federal efforts to improve graduation rates have helped pressure many schools to show gains, and skeptics caution that some schools are granting diplomas to students who lack the skills they need to succeed after high school.

According to the National Assessment of Educational Progress, known as the "Nation's Report Card," high school students have not shown academic progress in recent years: In 2015, high school seniors posted lower scores in reading than they did in 1992, and their math scores were unchanged across the past decade.